PROJECT SUMMARY/ABSTRACT Research Objectives. This prospective cohort study rigorously examines the neurocognitive impact of concussion on simulated and real-world driving performance among young drivers aged 16-24 years. Importance. Concussion impairs cognitive processing speed, attention, concentration and integration ? skills which are also important for safe driving. Unlike new ?Return to Learn? guidelines, there are no evidence-based ?Return to Drive? guidelines for when individuals with concussion may be safe to return to driving. Objectives. Conduct a prospective matched cohort study to explore the risk of concussion in simulated and real-world driving conditions. We propose three specific aims and a fourth exploratory aim: (i) Examine whether concussion negatively impacts simulated driving performance among young drivers, relative to a cohort of young drivers without concussion. (ii) Determine whether simulated driving task performance correlates with recovery from concussion symptoms and signs in the month following concussion, relative to young drivers without recent concussion. (iii) Measure the impact of concussion and recovery on real-world driving exposure and performance. (iv) [Exploratory] Examine whether concussion symptoms and neuropsychometric impairment are associated with higher rates of driving citations or reported crashes. Study design. Prospective controlled matched cohort study. Setting/participants. 50 drivers with recent concussion; 50 age/gender matched controls aged 16-25 years. Study protocol. Concussion participants will be recruited within two weeks of concussion. Case and control participants will complete 1) driving risk survey; 2) neuropsychological testing an 3) simulated driving tasks at baseline and 1 month. Commercially available monitoring technology will record risky driving for 3 months Outcome measures. (i) simulated driving risk scores; (ii) real world driving risk scores (rapid braking, rapid acceleration, speeding); (iii) reported citations and crash rates. Impact. This study will have a significant population health impact in elucidating the neurocognitive sequelae of recent concussion on driving. Results will inform return to safe driving among young drivers with concussion.